1. Field of the Invention
The invention relates to a medical device useful during minimally invasive procedures, such as laparoscopic procedures, for reducing the size of specimens so that they can be removed from a body by minimally invasive surgical techniques. The device further allows for the maintenance of sufficient tissue integrity to allow subsequent pathology.
2. Description of the Related Art
During the removal of a diseased gallbladder during cholecystectomy, an inflamed appendix during appendectomy, a kidney during nephrectomy, or other procedures requiring the removal of relatively large tissue masses, it is frequently necessary to remove objects that are larger than the cannula through which the procedure is being conducted. One method of reducing the size of such objects is to use a device such as a morcellator. A morcellator is used in conjunction with a suitable tissue isolation bag or container to mechanically reduce the size of the object by grinding, coring or shaving the object. The isolation bag can then either be wholly withdrawn from the site, or the neck of the bag can be externalized through the cannula or the puncture site and the now small pieces of tissue removed piece by piece. If such a device is not available, or is ineffective, the surgeon must increase the size of the hole through which he is working, which is not desirable. The available morcellators are generally very slow, which increases costs associated with the operating procedure, and frequently do not remove tissue in identifiable form, which does not allow later pathology. Such morcellators are exemplified by the hand device shown in FIG. 1, which is essentially a tubular structure 10 with a sharpened front edge 12 which is driven into a tissue sample in order to remove a core of tissue. The process of removing a core of tissue is repeated until the structure has been sufficiently reduced in size as to be extractable through the available opening. These hand operated devices are extremely slow and laborious.
A similar device for morcellating a tissue mass is shown in FIG. 2. The morcellator, has a power supply 16 for rotating a tubular cutter 18 within a concentric tube 20. This device requires a vacuum source 22 to suck the cored-out tissue into a receptacle 24. This device is awkward, slow, bulky, and requires ancillary equipment devoted to it alone. Therefore, this device is not always found in an operating room. The current invention offers a much improved method of tissue bulk reduction.
U.S. Pat. No. 5,037,379 discloses a surgical tissue bag for percutaneously debulking tissue. The debulking is performed by inserting the bag through an access sheath into a body cavity, inserting a surgically removed tissue mass through an open end of the bag, closing the end of the bag and pulling the closed end of the bag out of the body cavity. The end of the bag is then opened and morcellating or debulking of the tissue through the open end of the bag is performed while the remainder of the bag remains in the body cavity. The bag is made of flexible and foldable material and includes an inner layer of puncture resistant material such as nylon in either woven or solid layer form for resisting penetration by a surgical morcellating instrument. The outer layer of the bag is made of a moisture proof material such as plastisol.
U.S. Pat. No. 5,215,521 discloses an entrapment envelope having a means for opening and closing. The entrapment envelope is constructed of flexible, low fluid permeability materials having sufficient strength to contain morcellator entry, organ fragmentation and removal.
U.S. Pat. No. 5,337,754 discloses a tissue isolation bag which expands from a collapsed configuration to an expanded configuration when pressurized gas or liquid is supplied thereto.
U.S. Pat. No. 5,330,483 discloses a tissue reduction device which is thermally activated and is used in conjunction with a tissue isolation bag. The tissue reduction member is in an expanded condition at body temperature but shrinks to a smaller specimen reducing configuration when heated to a temperature above body temperature.